Synthetic diesel fuel and process for its production (law3 1 1)

Abstract

Diesel fuels or blending stocks having excellent lubricity, oxidative stability and high cetane number are produced from non-shifting Fischer-Tropsch processes by separating the Fischer-Tropsch product into a lighter and heavier fractions, e.g., at about 700° F., subjecting the 700° F.+ fraction to hydro-treating, and combining the 700° F.- portion of the hydrotreated product with the lighter fraction that has not been hydrotreated.

What is claimed is:  
     
       1. A process for producing a distillate fuel heavier than gasoline comprising: 
       (a) separating the product of a Fischer-Tropsch process into a heavier fraction and a lighter fraction;  
       (b) hydroisomerizing the heavier fraction at hydroisomerization conditions and recovering a 700° F.− fraction therefrom; and  
       (c) blending at least a portion of the recovered fraction of step (b) with at least a portion of the lighter fraction.  
     
     
       2. The process of  claim 1  wherein a product boiling in the range 250-700° F. is recovered from the blended product of step (c). 
     
     
       3. The process of  claim 2  wherein the recovered product of step (c) contains 0.001-0.3 wt % oxygen, water free basis. 
     
     
       4. The product of  claim 3 . 
     
     
       5. The process of  claim 2  wherein the lighter fraction is characterized by the absence of hydrotreating. 
     
     
       6. The process of  claim 2  wherein the lighter fraction contains C 12 + primary alcohols. 
     
     
       7. The process of  claim 6  wherein the lighter fraction contains essentially all of the C 12 -C 24  primary alcohols. 
     
     
       8. The process of  claim 2  wherein the Fischer-Tropsch process is characterized by non-shifting conditions.